It's good to know that the other 2 devices are able to connect to the wi-fi network. At least, that indicates that there's no problem with the router and the domestic network itself. Can you please, answer to these questions:
1. What operating system does the laptop have?
2. Since when you started receiving this type of error?
3. Have you tried connecting the laptop to another wi-fi network?
4. Adid you try connecting to Internet when using an Ethernet cable directly attached to the router's port?
When you have the time, come back to the topic to share more details. Cheers.